In this litigious society, even a police chase after a criminal can prove dangerous to the municipality, which sponsors the police department. Such a high speed police chase sometimes causes injury to the pursuing police officer or innocent victims, in addition to the offending motorist or other criminal.
Not only does an innocent party suffer improperly, he or she is also hurt substantially for merely being at the wrong place at the wrong time. This problem has become so severe that a number of states are even restricting high speed police chases by statute.
From both a military and civilian standpoint, it can be desirable to disable a vehicle, in a simple fashion without creating a danger to the surrounding area. Various known electronic devices are most ineffective. These devices can flatten tires or disable engines.
Known devices exist which can flatten or incapacitate a vehicle tire. If this occurs at a high speed, the driver may lose control of the vehicle. An uncontrolled vehicle is extremely dangerous. Whether the tire flattening device is electronically or mechanically actuated, it is highly desirable to disable the vehicle and incapacitate the escape mechanism without this danger of losing control of the vehicle.
In addition to the tire flattening device, an electronic device can disable a vehicle engine by attacking various vehicle systems. One such system is an electronic engine control computer. The second is the electronic sensors, which feed information to the electronic engine control computer. The third system is a set of sensors in the vehicle's signal processing modules. Damage to or destruction of the electronic engine control computer or electronic engine module will stop the vehicle by disabling the fuel delivery or ignition pulses. Damage to various sensors will usually cause activation of a redundant (also known as the limp home) mode where vehicle performance is drastically reduced.
A device in this class is generically known as an anti-vehicle electronic counter measure (AVECM). The high burst of pulsed microwave energy from one type of an electronic engine disabling device, while it may disable the criminal vehicle, can also disable adjacent computers and unintended vehicles. The microwave energy lacks control so severely, that the advantages of using the high microwave energy or similar disabling devices are far outweighed by the disadvantages.
Especially problematical is the production of the high burst of pulsed microwave energy by an electromagnetic pulse generating system. The transmission of this cannot be specifically directed to only desired target. This lack of direction can very adversely affect unintended vehicles as well as computers in nearby buildings.
Typically, a vehicle disabling device is desired to be of a type referred to as a man-portable barrier. In other words, the device may be carried by a man. Present man-portable barrier systems have significant technical shortcomings, because they must dissipate fully the kinetic energy of the target vehicle. This places severe technical constraints on any man-deployable system, requiring that they be light-weight, safe, rapidly deployable, and easy to operate by a small unit or patrol.
It is difficult for light-weight systems to sustain the kinetic energy dissipation rate required to stop a typical vehicle traveling at moderate to high speeds. A vehicle weighing 6,800 kilograms (15,000 pounds) and traveling at 80 kilometers per hour (50 miles per hour) has a kinetic energy of over 170,000 newton-meters (1.25 million foot-pounds), for example. The development of a system light enough to be man-deployable and able to sustain the mechanical forces required to dissipate that force is extremely difficult to realize.
In an attempt to avoid the direct dissipation of these immense kinetic forces, the traditional approach is to disable the target vehicle or operator by various means. These typically involve severe damage to the vehicle, driver, occupants, and even bystanding personnel. These means are, therefore, of questionable use in a civilian law enforcement environment.
Tire deflation and related techniques can be easily circumvented by current commercially available deflation-resistant, runflat, tire technology and means such as expanded cell polymer foam tire fillers. Even when tires are successfully deflated, forward progress can be maintained for a long distances, because the vehicle drive train is still operational.
Arresting the vehicle by mechanical disruption is extremely hazardous. Typical mechanical disruption is by small arms or ballistic projectiles. This method is intrinsically hazardous, especially in urban or populated areas and is not very reliable, as the projectiles must impact either a critical vehicle component or the driver, either of which presents considerable target acquisition problems because of target speed and maneuverability.
It is desired to avoid these dangers and such methods. In response, police and military security agents often pursue the target vehicles at high speeds which result in extreme hazards to these personnel and also to innocent bystanders, besides being frequently ineffective in arresting the target vehicle and its occupants.
Local, state, and federal police agencies are especially concerned with reducing or eliminating high speed pursuits or target vehicles because of the potentially disastrous effects on public and/or private property and the personal welfare of non-involved third parties. In addition to the almost unacceptable chance of hurting an innocent party, the financial costs thereof can be immense.
Civilian, private, and public security agencies and commercial organizations are equally concerned with prevention of unauthorized suspect or terrorist vehicle penetration. Therefore, development of AVECM technology and devices has great commercial as well as military applications, both domestically and internationally.
Other vehicle penetration systems also have shortcomings. Mechanical disruption of the vehicle by stationary and associated attached penetration is also hazardous and often ineffective. These systems attempt to use the vehicle's own kinetic energy to produce mechanical damage. These systems typically employ spikes, pikes, turnstiles, hooks, cables, or related kinetic pendulum-type devices.
The effectiveness of these devices is overly dependent on the vehicle's weight, physical design and configuration, speed vector of approach; which have, in fact, exhibited variable results in actual field use. These systems are also not readily deployable by a single man in the majority of cases.
Some non-traditional methods are developed in an attempt to overcome these problems. These include chemical agents, adhesives, and foams. These are also of questionable and unproven effectiveness and are potentially hazardous, non-selective. Additionally, these methods may pose a toxic or environmental hazard.
The methods of deployment of these chemical-based compounds require complex equipment. Typical parts of this equipment include, but are not limited to; nozzles, hoses, and pressure vessels. This complex equipment can malfunction or suffer damage from the chemicals themselves.
The effectiveness of these chemicals themselves may be compromised by environmental conditions, such as precipitation, temperature, humidity, wind, road surface characteristics and other factors. The use of caustic and toxic materials may also violate United States and international laws and regulations covering the use of chemicals in warfare.